Encyclopedia of Science: U
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
U Camelopardalis
U Geminorum star
UARS (Upper Atmosphere Research Satellite)
UBV system
UCF-1.01
Uchinoura Space Center
UFO (UHF Follow-On) satellites
Ulam, Stanislaw Marcin (1909–1984)
ulcer
Ulinski, Franz Abdon (1890–1974)
ulna
ulnar artery
ulnar nerve
Ultra Long-Duration Balloon Project
ultra-cool star
ultra-luminous cluster
ultra-luminous infrared galaxy
ultrasonics
ultrasound scanning
ultraviolet (UV)
ultraviolet lasers,
interstellar signaling via
Ulysses
umbilical cord
umbra
Umbriel
Ume
uncertainty principle
unconformity
uncountable set
undulating number
unduloid
UnEX (University-class Explorer)
unexpected hanging
ungulate
unicellular
unidentified flying objects (UFOs)
unified field theory
uniformitarianism
uniformity, principle of
uniform polyhedron
unilluminable room problem
union
unique number
unit fraction
United Kingdom Infrared Telescope
United Kingdom Schmidt Telescope
UNITS
units of electricity and magnetism
units of force, energy, and power
units of heat
units of length
units of luminance
units of mass
units of pressure
units of radioactivity and radiation dose
units of sound
units of temperature
units of time
units of volume
universal
universal computation
universal computer
Universal Library
Universal Time (UT)
universal translator
universe
University of California, Berkeley
untouchable number
Uosat
upside-down picture
Upsilon Andromedae
uracil
uranium
Uranus
Urca process
urea
ureilite
ureter
urethra
Urey, Harold Clayton (1893–1981)
uric acid
urinary bladder
urinary system
urine
Urodela (newts and salamaders)
urogenital disease
Ursa Major (constellation)
Ursa Major Moving Cluster
Ursa Minor (constellation)
Ursa Minor Dwarf
47 Ursae Majoris
US Air Force study on teleportation
US Naval Observatory
U-shaped valley
Usher syndrome
USRA (Universities Space Research Association)
Ussher, James (1581–1656)
uterine cancer
uterine cancer treatment
uterus
uterus, disorders of
utility function
Utopia Planitia
utricle
UU Herculis star
UV Ceti star
UV Raman and fluorescence
spectroscopy
uvea
uvula
UX Orionis